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#herbicide tolerance

3 public questions tagged with this topic.

Transgenic Plant -1

Sulfonyl urea resistance is due to mutation in:

Acetolactate synthase also called acetohydroxyacid synthase catalyzes first common step of branched-chain amino acid biosynthesis: condensation of two pyruvate molecules to acetolactate leading to valine and leucine, and condensation of pyruvate and 2-ketobutyrate to acetohydroxybutyrate leading to isoleucine. Sulfonylurea herbicides such as chlorsulfuron and tribenuron bind in substrate access channel of ALS, blocking access to catalytic site containing thiamine pyrophosphate. Resistance evolves via non-synonymous mutations in ALS gene altering herbicide binding pocket without abolishing cata

Ref: LaRossa Trends Biotech 1984 ALS mutation; Tranel Weed Sci 2002 ALS Pro197; NCBI NBK21601; PubMed 14769484 sulfonylurea resistance mechanism review.

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Transgenic Plant -1

Bialaphos resistance in plants is conferred by:

Bialaphos tripeptide herbicide consists of phosphinothricin plus two alanine residues. In plant tissue peptidases release active phosphinothricin, structural analog of glutamate that inhibits glutamine synthetase essential for assimilation of ammonia into glutamine. Inhibition causes ammonia accumulation, photosynthesis disruption, and rapid cell death. Bacterium Streptomyces hygroscopicus produces bialaphos and protects itself via bar gene encoding phosphinothricin acetyltransferase. Enzyme transfers acetyl group from acetyl-CoA to free amino group of phosphinothricin, producing N-acetyl phos

Ref: Murakami Mol Gen Genet 1986 bar Streptomyces; De Block EMBO J 1987 Basta resistance; NCBI NBK131103 bar function; PubMed 2884102.

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Transgenic Plant -1

Roundup Ready crops are resistant to:

Roundup Ready is brand name for transgenic crops tolerant to glyphosate based herbicide Roundup. Native crop EPSPS inhibited by glyphosate application, blocking aromatic amino acid synthesis. Incorporation of insensitive EPSPS variant allows continued pathway function despite spray, enabling post-emergence weed control without crop injury. Crops carrying cp4-epsps gene survive broadcast over-the-top application at commercial rates, simplifying weed management and facilitating conservation tillage reducing soil erosion. Soybean, cotton, maize, canola, alfalfa, and sugar beet versions deregulate

Ref: Dill GM Crops 2005 Roundup Ready; Funke PNAS 2006 CP4; NCBI NBK131103; ISAAA Pocket K 10 herbicide tolerance mechanism.

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